<template>
  <div class="app-container">
    <!--查询表单-->
    <el-card class="operate-container" shadow="never">
      <el-form :inline="true" class="demo-form-inline">

        <!-- 所属分类：级联下拉列表 -->
        <!-- 一级分类 -->
        <el-form-item label="课程类别">
          <el-select
            v-model="searchObj.subjectParentId"
            placeholder="请选择"
            @change="subjectLevelOneChanged">
            <el-option
              v-for="subject in subjectList"
              :key="subject.id"
              :label="subject.title"
              :value="subject.id"/>
          </el-select>

          <!-- 二级分类 -->
          <el-select v-model="searchObj.subjectId" placeholder="请选择">
            <el-option
              v-for="subject in subjectLevelTwoList"
              :key="subject.id"
              :label="subject.title"
              :value="subject.id"/>
          </el-select>
        </el-form-item>

        <!-- 标题 -->
        <el-form-item label="标题">
          <el-input v-model="searchObj.title" placeholder="课程标题"/>
        </el-form-item>
        <!-- 讲师 -->
        <el-form-item label="讲师">
          <el-select
            v-model="searchObj.teacherId"
            placeholder="请选择讲师">
            <el-option
              v-for="teacher in teacherList"
              :key="teacher.id"
              :label="teacher.name"
              :value="teacher.id"/>
          </el-select>
        </el-form-item>

        <el-button type="primary" icon="el-icon-search" @click="fetchData()">查询</el-button>
        <el-button type="default" @click="resetData()">清空</el-button>
      </el-form>
    </el-card>

    <!-- 工具按钮 -->
    <el-card class="operate-container" shadow="never">
      <i class="el-icon-tickets" style="margin-top: 5px"></i>
      <span style="margin-top: 5px">数据列表</span>
      <el-button class="btn-add" @click="add()">添加</el-button>
    </el-card>

    <!-- 表格 -->
    <el-table :data="list" border stripe>
      <el-table-column label="#" width="50">
        <template slot-scope="scope">
          {{ (page - 1) * limit + scope.$index + 1 }}
        </template>
      </el-table-column>

      <el-table-column label="封面" width="200" align="center">
        <template slot-scope="scope">
          <img :src="scope.row.cover" alt="scope.row.title" width="100%">
        </template>
      </el-table-column>
      <el-table-column label="课程信息">
        <template slot-scope="scope">
          <a href="">{{ scope.row.title }}</a>
          <p>
            分类：{{ scope.row.param.subjectParentTitle }} > {{ scope.row.param.subjectTitle }}
          </p>
          <p>
            课时：{{ scope.row.lessonNum }} /
            浏览：{{ scope.row.viewCount }} /
            付费学员：{{ scope.row.buyCount }}
          </p>
        </template>
      </el-table-column>
      <el-table-column label="讲师" width="100" align="center">
        <template slot-scope="scope">
          {{ scope.row.param.teacherName }}
        </template>
      </el-table-column>
      <el-table-column label="价格(元)" width="100" align="center" >
        <template slot-scope="scope">
          <!-- {{ typeof '0' }}  {{ typeof 0 }} {{ '0' == 0 }} -->
          <!-- {{ typeof scope.row.price }}
          {{ typeof Number(scope.row.price) }}
          {{ typeof Number(scope.row.price).toFixed(2) }} -->

          <el-tag v-if="Number(scope.row.price) === 0" type="success">免费</el-tag>

          <!-- 前端解决保留两位小数的问题 -->
          <!-- <el-tag v-else>{{ Number(scope.row.price).toFixed(2) }}</el-tag> -->

          <!-- 后端解决保留两位小数的问题，前端不用处理 -->
          <el-tag v-else>{{ scope.row.price }}</el-tag>
        </template>
      </el-table-column>
      <el-table-column prop="status" label="课程状态" width="100" align="center" >
        <template slot-scope="scope">
          <el-tag :type="scope.row.status === 0 ? 'warning' : 'success'">{{ scope.row.status === 0 ? '未发布' : '已发布' }}</el-tag>
        </template>
      </el-table-column>
      <el-table-column label="发布时间" width="140" align="center">
        <template slot-scope="scope">
          {{ scope.row.createTime ? scope.row.createTime.substr(0, 16) : '' }}
        </template>
      </el-table-column>

      <el-table-column label="操作" width="210" align="center">
        <template slot-scope="scope">
          <router-link :to="'/vodcourse/course/info/'+scope.row.id">
            <el-button type="text" icon="el-icon-edit" >修改</el-button>
          </router-link>
          <router-link :to="'/vodcourse/course/chapter/'+scope.row.id">
            <el-button type="text" icon="el-icon-edit" >编辑大纲</el-button>
          </router-link>
          <router-link :to="'/vodcourse/course/chart/'+scope.row.id">
            <el-button type="text" icon="el-icon-edit">课程统计</el-button>
          </router-link>
          <el-button type="text" icon="el-icon-delete" @click="removeById(scope.row.id)" >删除</el-button>
        </template>
      </el-table-column>
    </el-table>

    <!-- 分页组件 -->
    <el-pagination
      :current-page="page"
      :total="total"
      :page-size="limit"
      :page-sizes="[5, 10, 20, 30, 40, 50, 100]"
      style="padding: 30px 0; text-align: center;"
      layout="total, sizes, prev, pager, next, jumper"
      @size-change="changePageSize"
      @current-change="changeCurrentPage"
    />
  </div>
</template>

<script>
    import courseApi from '@/api/vod/course'
    import teacherApi from '@/api/vod/teacher'
    import subjectApi from '@/api/vod/subject'

    export default {

        data() {
            return {
                list: [], // 课程列表
                total: 0, // 总记录数
                page: 1, // 页码
                limit: 10, // 每页记录数
                searchObj: {
                    subjectId: ''// 解决查询表单无法选中二级类别
                }, // 查询条件
                teacherList: [], // 讲师列表
                subjectList: [], // 一级分类列表
                subjectLevelTwoList: [] // 二级分类列表,
            }
        },

        created() {
            this.fetchData()
            // 初始化分类列表
            this.initSubjectList()
            // 获取讲师列表
            this.initTeacherList()
        },

        methods: {

          // 根据id删除数据
            removeById(id) {
                this.$confirm('此操作将永久删除该课程，以及该课程下的章节和视频，是否继续?', '提示', {
                    confirmButtonText: '确定',
                    cancelButtonText: '取消',
                    type: 'warning'
                }).then(() => {
                    return courseApi.removeById(id)
                }).then(response => {
                    this.fetchData()
                    this.$message.success(response.message)
                }).catch((response) => { // 失败
                    if (response === 'cancel') {
                        this.$message.info('取消删除')
                    }
                })
            },

            fetchData() {
                courseApi.getPageList(this.page, this.limit, this.searchObj).then(response => {
                    this.list = response.data.records
                    console.log(this.list)
                    this.total = response.data.totalCount
                })
            },

            initTeacherList() {
                teacherApi.list().then(response => {
                    this.teacherList = response.data
                })
            },

            initSubjectList() {
                subjectApi.getChildList(0).then(response => {
                    this.subjectList = response.data
                })
            },

            subjectLevelOneChanged(value) {
                subjectApi.getChildList(value).then(response => {
                    this.subjectLevelTwoList = response.data
                    this.searchObj.subjectId = ''
                })
            },

            add() {
                this.$router.push({ path: '/vodcourse/course/info' })
            },

            // 每页记录数改变，size：回调参数，表示当前选中的“每页条数”
            changePageSize(size) {
                this.limit = size
                this.fetchData()
            },

            // 改变页码，page：回调参数，表示当前选中的“页码”
            changeCurrentPage(page) {
                this.page = page
                this.fetchData()
            },

            // 重置表单
            resetData() {
                this.searchObj = {}
                this.subjectLevelTwoList = [] // 二级分类列表
                this.fetchData()
            }
        }
    }
</script>

<style scoped>

</style>
